This weeks Tech Tuesday shows you how to drive model railway point motors with the Arduino microcontroller platform. In this video we show you how to program the Arduino to control a 16-channel 12V DC Relay Module. The module we use in the video is by sainsmart.com. This particular board requires a stable 12V DC supply, after looking at using the 12V DC supply from several analog DC train controllers, including the fixed accessory outputs, we discovered that the DC train controllers did not output a stable / clean enough 12V DC. At the start of the video we show you how to use an old PC-XT/AT power supply to provide a 12V and 5V bus for your Arduino model railway projects, then show you how to power the Arduino with this power source and how to power the 12V relay module.

Note: Some of the smaller (less than 16) channel relay boards use 5V DC or 3.3V DC instead of 12V. Check your boards specs before hooking up the power!

Source code can be found at https://github.com/oorail/arduino-rail/tree/master/point-motors/relay